Brain Network Analysis Reveals Hemispheric Aberrant Topology in Patients with idiopathic REM Sleep Behavior Disorder

Idiopathic rapid eye movement sleep behavior disorder (iRBD) is recognized as a prodromal stage of neuro-degenerative disease. While brain network analysis is a well-documented approach for characterizing disease-related dysfunctions, the specific patterns in iRBD, particularly those related to hemispheric aberrations remain largely unexplored. To address this gap, this study investigated the topological abnormalities of multi-band EEG networks in patients with iRBD. Specifically, eyes-open resting-state EEG signals were collected from 30 iRBD patients and 30 matched health control (HC) participants. Graph theoretical analysis was then employed to explore network properties at the whole-brain and the hemispheric level. At the whole-brain level, we found aberrant increased local and global efficiency along with a distinct pattern of increased frontal and decreased parietal nodal efficiency in the alpha band of iRBD patients. At the hemispheric level, iRBD networks displayed more efficient topological properties in the left hemisphere. Additionally, significant hemispheric asymmetry was observed in the alpha-band iRBD network compared to that of HC. In sum, these findings provide novel insights into the disrupted network reorganization in iRBD and suggest aberrant hemispheric asymmetry as a potential neural biomarker for early diagnosis and monitoring of the disease.